/*
* uvc_video.c -- USB Video Class driver - Video handling
*
* Copyright (C) 2005-2010
* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <linux/atomic.h>
#include <asm/unaligned.h>
#include <media/v4l2-common.h>
#include "uvcvideo.h"
/* ------------------------------------------------------------------------
* UVC Controls
*/
static int __uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
__u8 intfnum, __u8 cs, void *data, __u16 size,
int timeout)
{
__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
unsigned int pipe;
pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
: usb_sndctrlpipe(dev->udev, 0);
type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
return usb_control_msg(dev->udev, pipe, query, type, cs << 8,
unit << 8 | intfnum, data, size, timeout);
}
static const char *uvc_query_name(__u8 query)
{
switch (query) {
case UVC_SET_CUR:
return "SET_CUR";
case UVC_GET_CUR:
return "GET_CUR";
case UVC_GET_MIN:
return "GET_MIN";
case UVC_GET_MAX:
return "GET_MAX";
case UVC_GET_RES:
return "GET_RES";
case UVC_GET_LEN:
return "GET_LEN";
case UVC_GET_INFO:
return "GET_INFO";
case UVC_GET_DEF:
return "GET_DEF";
default:
return "<invalid>";
}
}
int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
__u8 intfnum, __u8 cs, void *data, __u16 size)
{
int ret;
ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
UVC_CTRL_CONTROL_TIMEOUT);
if (ret != size) {
uvc_printk(KERN_ERR, "Failed to query (%s) UVC control %u on "
"unit %u: %d (exp. %u).\n", uvc_query_name(query), cs,
unit, ret, size);
return -EIO;
}
return 0;
}
static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
struct uvc_streaming_control *ctrl)
{
struct uvc_format *format = NULL;
struct uvc_frame *frame = NULL;
unsigned int i;
for (i = 0; i < stream->nformats; ++i) {
if (stream->format[i].index == ctrl->bFormatIndex) {
format = &stream->format[i];
break;
}
}
if (format == NULL)
return;
for (i = 0; i < format->nframes; ++i) {
if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) {
frame = &format->frame[i];
break;
}
}
if (frame == NULL)
return;
if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
(ctrl->dwMaxVideoFrameSize == 0 &&
stream->dev->uvc_version < 0x0110))
ctrl->dwMaxVideoFrameSize =
frame->dwMaxVideoFrameBufferSize;
/* The "TOSHIBA Web Camera - 5M" Chicony device (04f2:b50b) seems to
* compute the bandwidth on 16 bits and erroneously sign-extend it to
* 32 bits, resulting in a huge bandwidth value. Detect and fix that
* condition by setting the 16 MSBs to 0 when they're all equal to 1.
*/
if ((ctrl->dwMaxPayloadTransferSize & 0xffff0000) == 0xffff0000)
ctrl->dwMaxPayloadTransferSize &= ~0xffff0000;
if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) &&
stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH &&
stream->intf->num_altsetting > 1) {
u32 interval;
u32 bandwidth;
interval = (ctrl->dwFrameInterval > 100000)
? ctrl->dwFrameInterval
: frame->dwFrameInterval[0];
/* Compute a bandwidth estimation by multiplying the frame
* size by the number of video frames per second, divide the
* result by the number of USB frames (or micro-frames for
* high-speed devices) per second and add the UVC header size
* (assumed to be 12 bytes long).
*/
bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp;
bandwidth *= 10000000 / interval + 1;
bandwidth /= 1000;
if (stream->dev->udev->speed == USB_SPEED_HIGH)
bandwidth /= 8;
bandwidth += 12;
/* The bandwidth estimate is too low for many cameras. Don't use
* maximum packet sizes lower than 1024 bytes to try and work
* around the problem. According to measurements done on two
* different camera models, the value is high enough to get most
* resolutions working while not preventing two simultaneous
* VGA streams at 15 fps.
*/
bandwidth = max_t(u32, bandwidth, 1024);
ctrl->dwMaxPayloadTransferSize = bandwidth;
}
}
static int uvc_get_video_ctrl(struct uvc_streaming *stream,
struct uvc_streaming_control *ctrl, int probe, __u8 query)
{
__u8 *data;
__u16 size;
int ret;
size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
query == UVC_GET_DEF)
return -EIO;
data = kmalloc(size, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
size, uvc_timeout_param);
if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) {
/* Some cameras, mostly based on Bison Electronics chipsets,
* answer a GET_MIN or GET_MAX request with the wCompQuality
* field only.
*/
uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non "
"compliance - GET_MIN/MAX(PROBE) incorrectly "
"supported. Enabling workaround.\n");
memset(ctrl, 0, sizeof *ctrl);
ctrl->wCompQuality = le16_to_cpup((__le16 *)data);
ret = 0;
goto out;
} else if (query == UVC_GET_DEF && probe == 1 && ret != size) {
/* Many cameras don't support the GET_DEF request on their
* video probe control. Warn once and return, the caller will
* fall back to GET_CUR.
*/
uvc_warn_once(stream->dev, UVC_WARN_PROBE_DEF, "UVC non "
"compliance - GET_DEF(PROBE) not supported. "
"Enabling workaround.\n");
ret = -EIO;
goto out;
} else if (ret != size) {
uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : "
"%d (exp. %u).\n", query, probe ? "probe" : "commit",
ret, size);
ret = -EIO;
goto out;
}
ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
ctrl->bFormatIndex = data[2];
ctrl->bFrameIndex = data[3];
ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]);
ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]);
if (size == 34) {
ctrl->dwClockFrequency = get_unaligned_le32(&data[26]);
ctrl->bmFramingInfo = data[30];
ctrl->bPreferedVersion = data[31];
ctrl->bMinVersion = data[32];
ctrl->bMaxVersion = data[33];
} else {
ctrl->dwClockFrequency = stream->dev->clock_frequency;
ctrl->bmFramingInfo = 0;
ctrl->bPreferedVersion = 0;
ctrl->bMinVersion = 0;
ctrl->bMaxVersion = 0;
}
/* Some broken devices return null or wrong dwMaxVideoFrameSize and
* dwMaxPayloadTransferSize fields. Try to get the value from the
* format and frame descriptors.
*/
uvc_fixup_video_ctrl(stream, ctrl);
ret = 0;
out:
kfree(data);
return ret;
}
static int uvc_set_video_ctrl(struct uvc_streaming *stream,
struct uvc_streaming_control *ctrl, int probe)
{
__u8 *data;
__u16 size;
int ret;
size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
data = kzalloc(size, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
*(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
data[2] = ctrl->bFormatIndex;
data[3] = ctrl->bFrameIndex;
*(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
*(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
*(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
*(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
*(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
*(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
if (size == 34) {
put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
data[30] = ctrl->bmFramingInfo;
data[31] = ctrl->bPreferedVersion;
data[32] = ctrl->bMinVersion;
data[33] = ctrl->bMaxVersion;
}
ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum,
probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
size, uvc_timeout_param);
if (ret != size) {
uvc_printk(KERN_ERR, "Failed to set UVC %s control : "
"%d (exp. %u).\n", probe ? "probe" : "commit",
ret, size);
ret = -EIO;
}
kfree(data);
return ret;
}
int uvc_probe_video(struct uvc_streaming *stream,
struct uvc_streaming_control *probe)
{
struct uvc_streaming_control probe_min, probe_max;
__u16 bandwidth;
unsigned int i;
int ret;
/* Perform probing. The device should adjust the requested values
* according to its capabilities. However, some devices, namely the
* first generation UVC Logitech webcams, don't implement the Video
* Probe control properly, and just return the needed bandwidth. For
* that reason, if the needed bandwidth exceeds the maximum available
* bandwidth, try to lower the quality.
*/
ret = uvc_set_video_ctrl(stream, probe, 1);
if (ret < 0)
goto done;
/* Get the minimum and maximum values for compression settings. */
if (!(stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) {
ret = uvc_get_video_ctrl(stream, &probe_min, 1, UVC_GET_MIN);
if (ret < 0)
goto done;
ret = uvc_get_video_ctrl(stream, &probe_max, 1, UVC_GET_MAX);
if (ret < 0)
goto done;
probe->wCompQuality = probe_max.wCompQuality;
}
for (i = 0; i < 2; ++i) {
ret = uvc_set_video_ctrl(stream, probe, 1);
if (ret < 0)
goto done;
ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
if (ret < 0)
goto done;
if (stream->intf->num_altsetting == 1)
break;
bandwidth = probe->dwMaxPayloadTransferSize;
if (bandwidth <= stream->maxpsize)
break;
if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
ret = -ENOSPC;
goto done;
}
/* TODO: negotiate compression parameters */
probe->wKeyFrameRate = probe_min.wKeyFrameRate;
probe->wPFrameRate = probe_min.wPFrameRate;
probe->wCompQuality = probe_max.wCompQuality;
probe->wCompWindowSize = probe_min.wCompWindowSize;
}
done:
return ret;
}
static int uvc_commit_video(struct uvc_streaming *stream,
struct uvc_streaming_control *probe)
{
return uvc_set_video_ctrl(stream, probe, 0);
}
/* -----------------------------------------------------------------------------
* Clocks and timestamps
*/
static inline void uvc_video_get_ts(struct timespec *ts)
{
if (uvc_clock_param == CLOCK_MONOTONIC)
ktime_get_ts(ts);
else
ktime_get_real_ts(ts);
}
static void
uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
const __u8 *data, int len)
{
struct uvc_clock_sample *sample;
unsigned int header_size;
bool has_pts = false;
bool has_scr = false;
unsigned long flags;
struct timespec ts;
u16 host_sof;
u16 dev_sof;
switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) {
case UVC_STREAM_PTS | UVC_STREAM_SCR:
header_size = 12;
has_pts = true;
has_scr = true;
break;
case UVC_STREAM_PTS:
header_size = 6;
has_pts = true;
break;
case UVC_STREAM_SCR:
header_size = 8;
has_scr = true;
break;
default:
header_size = 2;
break;
}
/* Check for invalid headers. */
if (len < header_size)
return;
/* Extract the timestamps:
*
* - store the frame PTS in the buffer structure
* - if the SCR field is present, retrieve the host SOF counter and
* kernel timestamps and store them with the SCR STC and SOF fields
* in the ring buffer
*/
if (has_pts && buf != NULL)
buf->pts = get_unaligned_le32(&data[2]);
if (!has_scr)
return;
/* To limit the amount of data, drop SCRs with an SOF identical to the
* previous one.
*/
dev_sof = get_unaligned_le16(&data[header_size - 2]);
if (dev_sof == stream->clock.last_sof)
return;
stream->clock.last_sof = dev_sof;
host_sof = usb_get_current_frame_number(stream->dev->udev);
uvc_video_get_ts(&ts);
/* The UVC specification allows device implementations that can't obtain
* the USB frame number to keep their own frame counters as long as they
* match the size and frequency of the frame number associated with USB
* SOF tokens. The SOF values sent by such devices differ from the USB
* SOF tokens by a fixed offset that needs to be estimated and accounted
* for to make timestamp recovery as accurate as possible.
*
* The offset is estimated the first time a device SOF value is received
* as the difference between the host and device SOF values. As the two
* SOF values can differ slightly due to transmission delays, consider
* that the offset is null if the difference is not higher than 10 ms
* (negative differences can not happen and are thus considered as an
* offset). The video commit control wDelay field should be used to
* compute a dynamic threshold instead of using a fixed 10 ms value, but
* devices don't report reliable wDelay values.
*
* See uvc_video_clock_host_sof() for an explanation regarding why only
* the 8 LSBs of the delta are kept.
*/
if (stream->clock.sof_offset == (u16)-1) {
u16 delta_sof = (host_sof - dev_sof) & 255;
if (delta_sof >= 10)
stream->clock.sof_offset = delta_sof;
else
stream->clock.sof_offset = 0;
}
dev_sof = (dev_sof + stream->clock.sof_offset) & 2047;
spin_lock_irqsave(&stream->clock.lock, flags);
sample = &stream->clock.samples[stream->clock.head];
sample->dev_stc = get_unaligned_le32(&data[header_size - 6]);
sample->dev_sof = dev_sof;
sample->host_sof = host_sof;
sample->host_ts = ts;
/* Update the sliding window head and count. */
stream->clock.head = (stream->clock.head + 1) % stream->clock.size;
if (stream->clock.count < stream->clock.size)
stream->clock.count++;
spin_unlock_irqrestore(&stream->clock.lock, flags);
}
static void uvc_video_clock_reset(struct uvc_streaming *stream)
{
struct uvc_clock *clock = &stream->clock;
clock->head = 0;
clock->count = 0;
clock->last_sof = -1;
clock->sof_offset = -1;
}
static int uvc_video_clock_init(struct uvc_streaming *stream)
{
struct uvc_clock *clock = &stream->clock;
spin_lock_init(&clock->lock);
clock->size = 32;
clock->samples = kmalloc(clock->size * sizeof(*clock->samples),
GFP_KERNEL);
if (clock->samples == NULL)
return -ENOMEM;
uvc_video_clock_reset(stream);
return 0;
}
static void uvc_video_clock_cleanup(struct uvc_streaming *stream)
{
kfree(stream->clock.samples);
stream->clock.samples = NULL;
}
/*
* uvc_video_clock_host_sof - Return the host SOF value for a clock sample
*
* Host SOF counters reported by usb_get_current_frame_number() usually don't
* cover the whole 11-bits SOF range (0-2047) but are limited to the HCI frame
* schedule window. They can be limited to 8, 9 or 10 bits depending on the host
* controller and its configuration.
*
* We thus need to recover the SOF value corresponding to the host frame number.
* As the device and host frame numbers are sampled in a short interval, the
* difference between their values should be equal to a small delta plus an
* integer multiple of 256 caused by the host frame number limited precision.
*
* To obtain the recovered host SOF value, compute the small delta by masking
* the high bits of the host frame counter and device SOF difference and add it
* to the device SOF value.
*/
static u16 uvc_video_clock_host_sof(const struct uvc_clock_sample *sample)
{
/* The delta value can be negative. */
s8 delta_sof;
delta_sof = (sample->host_sof - sample->dev_sof) & 255;
return (sample->dev_sof + delta_sof) & 2047;
}
/*
* uvc_video_clock_update - Update the buffer timestamp
*
* This function converts the buffer PTS timestamp to the host clock domain by
* going through the USB SOF clock domain and stores the result in the V4L2
* buffer timestamp field.
*
* The relationship between the device clock and the host clock isn't known.
* However, the device and the host share the common USB SOF clock which can be
* used to recover that relationship.
*
* The relationship between the device clock and the USB SOF clock is considered
* to be linear over the clock samples sliding window and is given by
*
* SOF = m * PTS + p
*
* Several methods to compute the slope (m) and intercept (p) can be used. As
* the clock drift should be small compared to the sliding window size, we
* assume that the line that goes through the points at both ends of the window
* is a good approximation. Naming those points P1 and P2, we get
*
* SOF = (SOF2 - SOF1) / (STC2 - STC1) * PTS
* + (SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1)
*
* or
*
* SOF = ((SOF2 - SOF1) * PTS + SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1) (1)
*
* to avoid losing precision in the division. Similarly, the host timestamp is
* computed with
*
* TS = ((TS2 - TS1) * PTS + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1) (2)
*
* SOF values are coded on 11 bits by USB. We extend their precision with 16
* decimal bits, leading to a 11.16 coding.
*
* TODO: To avoid surprises with device clock values, PTS/STC timestamps should
* be normalized using the nominal device clock frequency reported through the
* UVC descriptors.
*
* Both the PTS/STC and SOF counters roll over, after a fixed but device
* specific amount of time for PTS/STC and after 2048ms for SOF. As long as the
* sliding window size is smaller than the rollover period, differences computed
* on unsigned integers will produce the correct result. However, the p term in
* the linear relations will be miscomputed.
*
* To fix the issue, we subtract a constant from the PTS and STC values to bring
* PTS to half the 32 bit STC range. The sliding window STC values then fit into
* the 32 bit range without any rollover.
*
* Similarly, we add 2048 to the device SOF values to make sure that the SOF
* computed by (1) will never be smaller than 0. This offset is then compensated
* by adding 2048 to the SOF values used in (2). However, this doesn't prevent
* rollovers between (1) and (2): the SOF value computed by (1) can be slightly
* lower than 4096, and the host SOF counters can have rolled over to 2048. This
* case is handled by subtracting 2048 from the SOF value if it exceeds the host
* SOF value at the end of the sliding window.
*
* Finally we subtract a constant from the host timestamps to bring the first
* timestamp of the sliding window to 1s.
*/
void uvc_video_clock_update(struct uvc_streaming *stream,
struct vb2_v4l2_buffer *vbuf,
struct uvc_buffer *buf)
{
struct uvc_clock *clock = &stream->clock;
struct uvc_clock_sample *first;
struct uvc_clock_sample *last;
unsigned long flags;
struct timespec ts;
u32 delta_stc;
u32 y1, y2;
u32 x1, x2;
u32 mean;
u32 sof;
u32 div;
u32 rem;
u64 y;
if (!uvc_hw_timestamps_param)
return;
spin_lock_irqsave(&clock->lock, flags);
if (clock->count < clock->size)
goto done;
first = &clock->samples[clock->head];
last = &clock->samples[(clock->head - 1) % clock->size];
/* First step, PTS to SOF conversion. */
delta_stc = buf->pts - (1UL << 31);
x1 = first->dev_stc - delta_stc;
x2 = last->dev_stc - delta_stc;
if (x1 == x2)
goto done;
y1 = (first->dev_sof + 2048) << 16;
y2 = (last->dev_sof + 2048) << 16;
if (y2 < y1)
y2 += 2048 << 16;
y = (u64)(y2 - y1) * (1ULL << 31) + (u64)y1 * (u64)x2
- (u64)y2 * (u64)x1;
y = div_u64(y, x2 - x1);
sof = y;
uvc_trace(UVC_TRACE_CLOCK, "%s: PTS %u y %llu.%06llu SOF %u.%06llu "
"(x1 %u x2 %u y1 %u y2 %u SOF offset %u)\n",
stream->dev->name, buf->pts,
y >> 16, div_u64((y & 0xffff) * 1000000, 65536),
sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),
x1, x2, y1, y2, clock->sof_offset);
/* Second step, SOF to host clock conversion. */
x1 = (uvc_video_clock_host_sof(first) + 2048) << 16;
x2 = (uvc_video_clock_host_sof(last) + 2048) << 16;
if (x2 < x1)
x2 += 2048 << 16;
if (x1 == x2)
goto done;
ts = timespec_sub(last->host_ts, first->host_ts);
y1 = NSEC_PER_SEC;
y2 = (ts.tv_sec + 1) * NSEC_PER_SEC + ts.tv_nsec;
/* Interpolated and host SOF timestamps can wrap around at slightly
* different times. Handle this by adding or removing 2048 to or from
* the computed SOF value to keep it close to the SOF samples mean
* value.
*/
mean = (x1 + x2) / 2;
if (mean - (1024 << 16) > sof)
sof += 2048 << 16;
else if (sof > mean + (1024 << 16))
sof -= 2048 << 16;
y = (u64)(y2 - y1) * (u64)sof + (u64)y1 * (u64)x2
- (u64)y2 * (u64)x1;
y = div_u64(y, x2 - x1);
div = div_u64_rem(y, NSEC_PER_SEC, &rem);
ts.tv_sec = first->host_ts.tv_sec - 1 + div;
ts.tv_nsec = first->host_ts.tv_nsec + rem;
if (ts.tv_nsec >= NSEC_PER_SEC) {
ts.tv_sec++;
ts.tv_nsec -= NSEC_PER_SEC;
}
uvc_trace(UVC_TRACE_CLOCK, "%s: SOF %u.%06llu y %llu ts %llu "
"buf ts %llu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %u)\n",
stream->dev->name,
sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),
y, timespec_to_ns(&ts), vbuf->vb2_buf.timestamp,
x1, first->host_sof, first->dev_sof,
x2, last->host_sof, last->dev_sof, y1, y2);
/* Update the V4L2 buffer. */
vbuf->vb2_buf.timestamp = timespec_to_ns(&ts);
done:
spin_unlock_irqrestore(&clock->lock, flags);
}
/* ------------------------------------------------------------------------
* Stream statistics
*/
static void uvc_video_stats_decode(struct uvc_streaming *stream,
const __u8 *data, int len)
{
unsigned int header_size;
bool has_pts = false;
bool has_scr = false;
u16 uninitialized_var(scr_sof);
u32 uninitialized_var(scr_stc);
u32 uninitialized_var(pts);
if (stream->stats.stream.nb_frames == 0 &&
stream->stats.frame.nb_packets == 0)
ktime_get_ts(&stream->stats.stream.start_ts);
switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) {
case UVC_STREAM_PTS | UVC_STREAM_SCR:
header_size = 12;
has_pts = true;
has_scr = true;
break;
case UVC_STREAM_PTS:
header_size = 6;
has_pts = true;
break;
case UVC_STREAM_SCR:
header_size = 8;
has_scr = true;
break;
default:
header_size = 2;
break;
}
/* Check for invalid headers. */
if (len < header_size || data[0] < header_size) {
stream->stats.frame.nb_invalid++;
return;
}
/* Extract the timestamps. */
if (has_pts)
pts = get_unaligned_le32(&data[2]);
if (has_scr) {
scr_stc = get_unaligned_le32(&data[header_size - 6]);
scr_sof = get_unaligned_le16(&data[header_size - 2]);
}
/* Is PTS constant through the whole frame ? */
if (has_pts && stream->stats.frame.nb_pts) {
if (stream->stats.frame.pts != pts) {
stream->stats.frame.nb_pts_diffs++;
stream->stats.frame.last_pts_diff =
stream->stats.frame.nb_packets;
}
}
if (has_pts) {
stream->stats.frame.nb_pts++;
stream->stats.frame.pts = pts;
}
/* Do all frames have a PTS in their first non-empty packet, or before
* their first empty packet ?
*/
if (stream->stats.frame.size == 0) {
if (len > header_size)
stream->stats.frame.has_initial_pts = has_pts;
if (len == header_size && has_pts)
stream->stats.frame.has_early_pts = true;
}
/* Do the SCR.STC and SCR.SOF fields vary through the frame ? */
if (has_scr && stream->stats.frame.nb_scr) {
if (stream->stats.frame.scr_stc != scr_stc)
stream->stats.frame.nb_scr_diffs++;
}
if (has_scr) {
/* Expand the SOF counter to 32 bits and store its value. */
if (stream->stats.stream.nb_frames > 0 ||
stream->stats.frame.nb_scr > 0)
stream->stats.stream.scr_sof_count +=
(scr_sof - stream->stats.stream.scr_sof) % 2048;
stream->stats.stream.scr_sof = scr_sof;
stream->stats.frame.nb_scr++;
stream->stats.frame.scr_stc = scr_stc;
stream->stats.frame.scr_sof = scr_sof;
if (scr_sof < stream->stats.stream.min_sof)
stream->stats.stream.min_sof = scr_sof;
if (scr_sof > stream->stats.stream.max_sof)
stream->stats.stream.max_sof = scr_sof;
}
/* Record the first non-empty packet number. */
if (stream->stats.frame.size == 0 && len > header_size)
stream->stats.frame.first_data = stream->stats.frame.nb_packets;
/* Update the frame size. */
stream->stats.frame.size += len - header_size;
/* Update the packets counters. */
stream->stats.frame.nb_packets++;
if (len > header_size)
stream->stats.frame.nb_empty++;
if (data[1] & UVC_STREAM_ERR)
stream->stats.frame.nb_errors++;
}
static void uvc_video_stats_update(struct uvc_streaming *stream)
{
struct uvc_stats_frame *frame = &stream->stats.frame;
uvc_trace(UVC_TRACE_STATS, "frame %u stats: %u/%u/%u packets, "
"%u/%u/%u pts (%searly %sinitial), %u/%u scr, "
"last pts/stc/sof %u/%u/%u\n",
stream->sequence, frame->first_data,
frame->nb_packets - frame->nb_empty, frame->nb_packets,
frame->nb_pts_diffs, frame->last_pts_diff, frame->nb_pts,
frame->has_early_pts ? "" : "!",
frame->has_initial_pts ? "" : "!",
frame->nb_scr_diffs, frame->nb_scr,
frame->pts, frame->scr_stc, frame->scr_sof);
stream->stats.stream.nb_frames++;
stream->stats.stream.nb_packets += stream->stats.frame.nb_packets;
stream->stats.stream.nb_empty += stream->stats.frame.nb_empty;
stream->stats.stream.nb_errors += stream->stats.frame.nb_errors;
stream->stats.stream.nb_invalid += stream->stats.frame.nb_invalid;
if (frame->has_early_pts)
stream->stats.stream.nb_pts_early++;
if (frame->has_initial_pts)
stream->stats.stream.nb_pts_initial++;
if (frame->last_pts_diff <= frame->first_data)
stream->stats.stream.nb_pts_constant++;
if (frame->nb_scr >= frame->nb_packets - frame->nb_empty)
stream->stats.stream.nb_scr_count_ok++;
if (frame->nb_scr_diffs + 1 == frame->nb_scr)
stream->stats.stream.nb_scr_diffs_ok++;
memset(&stream->stats.frame, 0, sizeof(stream->stats.frame));
}
size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf,
size_t size)
{
unsigned int scr_sof_freq;
unsigned int duration;
struct timespec ts;
size_t count = 0;
ts.tv_sec = stream->stats.stream.stop_ts.tv_sec
- stream->stats.stream.start_ts.tv_sec;
ts.tv_nsec = stream->stats.stream.stop_ts.tv_nsec
- stream->stats.stream.start_ts.tv_nsec;
if (ts.tv_nsec < 0) {
ts.tv_sec--;
ts.tv_nsec += 1000000000;
}
/* Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF
* frequency this will not overflow before more than 1h.
*/
duration = ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
if (duration != 0)
scr_sof_freq = stream->stats.stream.scr_sof_count * 1000
/ duration;
else
scr_sof_freq = 0;
count += scnprintf(buf + count, size - count,
"frames: %u\npackets: %u\nempty: %u\n"
"errors: %u\ninvalid: %u\n",
stream->stats.stream.nb_frames,
stream->stats.stream.nb_packets,
stream->stats.stream.nb_empty,
stream->stats.stream.nb_errors,
stream->stats.stream.nb_invalid);
count += scnprintf(buf + count, size - count,
"pts: %u early, %u initial, %u ok\n",
stream->stats.stream.nb_pts_early,
stream->stats.stream.nb_pts_initial,
stream->stats.stream.nb_pts_constant);
count += scnprintf(buf + count, size - count,
"scr: %u count ok, %u diff ok\n",
stream->stats.stream.nb_scr_count_ok,
stream->stats.stream.nb_scr_diffs_ok);
count += scnprintf(buf + count, size - count,
"sof: %u <= sof <= %u, freq %u.%03u kHz\n",
stream->stats.stream.min_sof,
stream->stats.stream.max_sof,
scr_sof_freq / 1000, scr_sof_freq % 1000);
return count;
}
static void uvc_video_stats_start(struct uvc_streaming *stream)
{
memset(&stream->stats, 0, sizeof(stream->stats));
stream->stats.stream.min_sof = 2048;
}
static void uvc_video_stats_stop(struct uvc_streaming *stream)
{
ktime_get_ts(&stream->stats.stream.stop_ts);
}
/* ------------------------------------------------------------------------
* Video codecs
*/
/* Video payload decoding is handled by uvc_video_decode_start(),
* uvc_video_decode_data() and uvc_video_decode_end().
*
* uvc_video_decode_start is called with URB data at the start of a bulk or
* isochronous payload. It processes header data and returns the header size
* in bytes if successful. If an error occurs, it returns a negative error
* code. The following error codes have special meanings.
*
* - EAGAIN informs the caller that the current video buffer should be marked
* as done, and that the function should be called again with the same data
* and a new video buffer. This is used when end of frame conditions can be
* reliably detected at the beginning of the next frame only.
*
* If an error other than -EAGAIN is returned, the caller will drop the current
* payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
* made until the next payload. -ENODATA can be used to drop the current
* payload if no other error code is appropriate.
*
* uvc_video_decode_data is called for every URB with URB data. It copies the
* data to the video buffer.
*
* uvc_video_decode_end is called with header data at the end of a bulk or
* isochronous payload. It performs any additional header data processing and
* returns 0 or a negative error code if an error occurred. As header data have
* already been processed by uvc_video_decode_start, this functions isn't
* required to perform sanity checks a second time.
*
* For isochronous transfers where a payload is always transferred in a single
* URB, the three functions will be called in a row.
*
* To let the decoder process header data and update its internal state even
* when no video buffer is available, uvc_video_decode_start must be prepared
* to be called with a NULL buf parameter. uvc_video_decode_data and
* uvc_video_decode_end will never be called with a NULL buffer.
*/
static int uvc_video_decode_start(struct uvc_streaming *stream,
struct uvc_buffer *buf, const __u8 *data, int len)
{
__u8 fid;
/* Sanity checks:
* - packet must be at least 2 bytes long
* - bHeaderLength value must be at least 2 bytes (see above)
* - bHeaderLength value can't be larger than the packet size.
*/
if (len < 2 || data[0] < 2 || data[0] > len) {
stream->stats.frame.nb_invalid++;
return -EINVAL;
}
fid = data[1] & UVC_STREAM_FID;
/* Increase the sequence number regardless of any buffer states, so
* that discontinuous sequence numbers always indicate lost frames.
*/
if (stream->last_fid != fid) {
stream->sequence++;
if (stream->sequence)
uvc_video_stats_update(stream);
}
uvc_video_clock_decode(stream, buf, data, len);
uvc_video_stats_decode(stream, data, len);
/* Store the payload FID bit and return immediately when the buffer is
* NULL.
*/
if (buf == NULL) {
stream->last_fid = fid;
return -ENODATA;
}
/* Mark the buffer as bad if the error bit is set. */
if (data[1] & UVC_STREAM_ERR) {
uvc_trace(UVC_TRACE_FRAME, "Marking buffer as bad (error bit "
"set).\n");
buf->error = 1;
}
/* Synchronize to the input stream by waiting for the FID bit to be
* toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
* stream->last_fid is initialized to -1, so the first isochronous
* frame will always be in sync.
*
* If the device doesn't toggle the FID bit, invert stream->last_fid
* when the EOF bit is set to force synchronisation on the next packet.
*/
if (buf->state != UVC_BUF_STATE_ACTIVE) {
struct timespec ts;
if (fid == stream->last_fid) {
uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
"sync).\n");
if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&
(data[1] & UVC_STREAM_EOF))
stream->last_fid ^= UVC_STREAM_FID;
return -ENODATA;
}
uvc_video_get_ts(&ts);
buf->buf.field = V4L2_FIELD_NONE;
buf->buf.sequence = stream->sequence;
buf->buf.vb2_buf.timestamp = timespec_to_ns(&ts);
/* TODO: Handle PTS and SCR. */
buf->state = UVC_BUF_STATE_ACTIVE;
}
/* Mark the buffer as done if we're at the beginning of a new frame.
* End of frame detection is better implemented by checking the EOF
* bit (FID bit toggling is delayed by one frame compared to the EOF
* bit), but some devices don't set the bit at end of frame (and the
* last payload can be lost anyway). We thus must check if the FID has
* been toggled.
*
* stream->last_fid is initialized to -1, so the first isochronous
* frame will never trigger an end of frame detection.
*
* Empty buffers (bytesused == 0) don't trigger end of frame detection
* as it doesn't make sense to return an empty buffer. This also
* avoids detecting end of frame conditions at FID toggling if the
* previous payload had the EOF bit set.
*/
if (fid != stream->last_fid && buf->bytesused != 0) {
uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
"toggled).\n");
buf->state = UVC_BUF_STATE_READY;
return -EAGAIN;
}
stream->last_fid = fid;
return data[0];
}
static void uvc_video_decode_data(struct uvc_streaming *stream,
struct uvc_buffer *buf, const __u8 *data, int len)
{
unsigned int maxlen, nbytes;
void *mem;
if (len <= 0)
return;
/* Copy the video data to the buffer. */
maxlen = buf->length - buf->bytesused;
mem = buf->mem + buf->bytesused;
nbytes = min((unsigned int)len, maxlen);
memcpy(mem, data, nbytes);
buf->bytesused += nbytes;
/* Complete the current frame if the buffer size was exceeded. */
if (len > maxlen) {
uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
buf->state = UVC_BUF_STATE_READY;
}
}
static void uvc_video_decode_end(struct uvc_streaming *stream,
struct uvc_buffer *buf, const __u8 *data, int len)
{
/* Mark the buffer as done if the EOF marker is set. */
if (data[1] & UVC_STREAM_EOF && buf->bytesused != 0) {
uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
if (data[0] == len)
uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
buf->state = UVC_BUF_STATE_READY;
if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
stream->last_fid ^= UVC_STREAM_FID;
}
}
/* Video payload encoding is handled by uvc_video_encode_header() and
* uvc_video_encode_data(). Only bulk transfers are currently supported.
*
* uvc_video_encode_header is called at the start of a payload. It adds header
* data to the transfer buffer and returns the header size. As the only known
* UVC output device transfers a whole frame in a single payload, the EOF bit
* is always set in the header.
*
* uvc_video_encode_data is called for every URB and copies the data from the
* video buffer to the transfer buffer.
*/
static int uvc_video_encode_header(struct uvc_streaming *stream,
struct uvc_buffer *buf, __u8 *data, int len)
{
data[0] = 2; /* Header length */
data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF
| (stream->last_fid & UVC_STREAM_FID);
return 2;
}
static int uvc_video_encode_data(struct uvc_streaming *stream,
struct uvc_buffer *buf, __u8 *data, int len)
{
struct uvc_video_queue *queue = &stream->queue;
unsigned int nbytes;
void *mem;
/* Copy video data to the URB buffer. */
mem = buf->mem + queue->buf_used;
nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used);
nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size,
nbytes);
memcpy(data, mem, nbytes);
queue->buf_used += nbytes;
return nbytes;
}
/* ------------------------------------------------------------------------
* URB handling
*/
/*
* Set error flag for incomplete buffer.
*/
static void uvc_video_validate_buffer(const struct uvc_streaming *stream,
struct uvc_buffer *buf)
{
if (stream->ctrl.dwMaxVideoFrameSize != buf->bytesused &&
!(stream->cur_format->flags & UVC_FMT_FLAG_COMPRESSED))
buf->error = 1;
}
/*
* Completion handler for video URBs.
*/
static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
struct uvc_buffer *buf)
{
u8 *mem;
int ret, i;
for (i = 0; i < urb->number_of_packets; ++i) {
if (urb->iso_frame_desc[i].status < 0) {
uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
"lost (%d).\n", urb->iso_frame_desc[i].status);
/* Mark the buffer as faulty. */
if (buf != NULL)
buf->error = 1;
continue;
}
/* Decode the payload header. */
mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
do {
ret = uvc_video_decode_start(stream, buf, mem,
urb->iso_frame_desc[i].actual_length);
if (ret == -EAGAIN) {
uvc_video_validate_buffer(stream, buf);
buf = uvc_queue_next_buffer(&stream->queue,
buf);
}
} while (ret == -EAGAIN);
if (ret < 0)
continue;
/* Decode the payload data. */
uvc_video_decode_data(stream, buf, mem + ret,
urb->iso_frame_desc[i].actual_length - ret);
/* Process the header again. */
uvc_video_decode_end(stream, buf, mem,
urb->iso_frame_desc[i].actual_length);
if (buf->state == UVC_BUF_STATE_READY) {
uvc_video_validate_buffer(stream, buf);
buf = uvc_queue_next_buffer(&stream->queue, buf);
}
}
}
static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
struct uvc_buffer *buf)
{
u8 *mem;
int len, ret;
/*
* Ignore ZLPs if they're not part of a frame, otherwise process them
* to trigger the end of payload detection.
*/
if (urb->actual_length == 0 && stream->bulk.header_size == 0)
return;
mem = urb->transfer_buffer;
len = urb->actual_length;
stream->bulk.payload_size += len;
/* If the URB is the first of its payload, decode and save the
* header.
*/
if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) {
do {
ret = uvc_video_decode_start(stream, buf, mem, len);
if (ret == -EAGAIN)
buf = uvc_queue_next_buffer(&stream->queue,
buf);
} while (ret == -EAGAIN);
/* If an error occurred skip the rest of the payload. */
if (ret < 0 || buf == NULL) {
stream->bulk.skip_payload = 1;
} else {
memcpy(stream->bulk.header, mem, ret);
stream->bulk.header_size = ret;
mem += ret;
len -= ret;
}
}
/* The buffer queue might have been cancelled while a bulk transfer
* was in progress, so we can reach here with buf equal to NULL. Make
* sure buf is never dereferenced if NULL.
*/
/* Process video data. */
if (!stream->bulk.skip_payload && buf != NULL)
uvc_video_decode_data(stream, buf, mem, len);
/* Detect the payload end by a URB smaller than the maximum size (or
* a payload size equal to the maximum) and process the header again.
*/
if (urb->actual_length < urb->transfer_buffer_length ||
stream->bulk.payload_size >= stream->bulk.max_payload_size) {
if (!stream->bulk.skip_payload && buf != NULL) {
uvc_video_decode_end(stream, buf, stream->bulk.header,
stream->bulk.payload_size);
if (buf->state == UVC_BUF_STATE_READY)
buf = uvc_queue_next_buffer(&stream->queue,
buf);
}
stream->bulk.header_size = 0;
stream->bulk.skip_payload = 0;
stream->bulk.payload_size = 0;
}
}
static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
struct uvc_buffer *buf)
{
u8 *mem = urb->transfer_buffer;
int len = stream->urb_size, ret;
if (buf == NULL) {
urb->transfer_buffer_length = 0;
return;
}
/* If the URB is the first of its payload, add the header. */
if (stream->bulk.header_size == 0) {
ret = uvc_video_encode_header(stream, buf, mem, len);
stream->bulk.header_size = ret;
stream->bulk.payload_size += ret;
mem += ret;
len -= ret;
}
/* Process video data. */
ret = uvc_video_encode_data(stream, buf, mem, len);
stream->bulk.payload_size += ret;
len -= ret;
if (buf->bytesused == stream->queue.buf_used ||
stream->bulk.payload_size == stream->bulk.max_payload_size) {
if (buf->bytesused == stream->queue.buf_used) {
stream->queue.buf_used = 0;
buf->state = UVC_BUF_STATE_READY;
buf->buf.sequence = ++stream->sequence;
uvc_queue_next_buffer(&stream->queue, buf);
stream->last_fid ^= UVC_STREAM_FID;
}
stream->bulk.header_size = 0;
stream->bulk.payload_size = 0;
}
urb->transfer_buffer_length = stream->urb_size - len;
}
static void uvc_video_complete(struct urb *urb)
{
struct uvc_streaming *stream = urb->context;
struct uvc_video_queue *queue = &stream->queue;
struct uvc_buffer *buf = NULL;
unsigned long flags;
int ret;
switch (urb->status) {
case 0:
break;
default:
uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
"completion handler.\n", urb->status);
case -ENOENT: /* usb_kill_urb() called. */
if (stream->frozen)
return;
case -ECONNRESET: /* usb_unlink_urb() called. */
case -ESHUTDOWN: /* The endpoint is being disabled. */
uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
return;
}
spin_lock_irqsave(&queue->irqlock, flags);
if (!list_empty(&queue->irqqueue))
buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
queue);
spin_unlock_irqrestore(&queue->irqlock, flags);
stream->decode(urb, stream, buf);
if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
ret);
}
}
/*
* Free transfer buffers.
*/
static void uvc_free_urb_buffers(struct uvc_streaming *stream)
{
unsigned int i;
for (i = 0; i < UVC_URBS; ++i) {
if (stream->urb_buffer[i]) {
#ifndef [31mCONFIG_DMA_NONCOHERENT[0m
usb_free_coherent(stream->dev->udev, stream->urb_size,
stream->urb_buffer[i], stream->urb_dma[i]);
#else
kfree(stream->urb_buffer[i]);
#endif
stream->urb_buffer[i] = NULL;
}
}
stream->urb_size = 0;
}
/*
* Allocate transfer buffers. This function can be called with buffers
* already allocated when resuming from suspend, in which case it will
* return without touching the buffers.
*
* Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the
* system is too low on memory try successively smaller numbers of packets
* until allocation succeeds.
*
* Return the number of allocated packets on success or 0 when out of memory.
*/
static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
unsigned int size, unsigned int psize, gfp_t gfp_flags)
{
unsigned int npackets;
unsigned int i;
/* Buffers are already allocated, bail out. */
if (stream->urb_size)
return stream->urb_size / psize;
/* Compute the number of packets. Bulk endpoints might transfer UVC
* payloads across multiple URBs.
*/
npackets = DIV_ROUND_UP(size, psize);
if (npackets > UVC_MAX_PACKETS)
npackets = UVC_MAX_PACKETS;
/* Retry allocations until one succeed. */
for (; npackets > 1; npackets /= 2) {
for (i = 0; i < UVC_URBS; ++i) {
stream->urb_size = psize * npackets;
#ifndef [31mCONFIG_DMA_NONCOHERENT[0m
stream->urb_buffer[i] = usb_alloc_coherent(
stream->dev->udev, stream->urb_size,
gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
#else
stream->urb_buffer[i] =
kmalloc(stream->urb_size, gfp_flags | __GFP_NOWARN);
#endif
if (!stream->urb_buffer[i]) {
uvc_free_urb_buffers(stream);
break;
}
}
if (i == UVC_URBS) {
uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB buffers "
"of %ux%u bytes each.\n", UVC_URBS, npackets,
psize);
return npackets;
}
}
uvc_trace(UVC_TRACE_VIDEO, "Failed to allocate URB buffers (%u bytes "
"per packet).\n", psize);
return 0;
}
/*
* Uninitialize isochronous/bulk URBs and free transfer buffers.
*/
static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
{
struct urb *urb;
unsigned int i;
uvc_video_stats_stop(stream);
for (i = 0; i < UVC_URBS; ++i) {
urb = stream->urb[i];
if (urb == NULL)
continue;
usb_kill_urb(urb);
usb_free_urb(urb);
stream->urb[i] = NULL;
}
if (free_buffers)
uvc_free_urb_buffers(stream);
}
/*
* Compute the maximum number of bytes per interval for an endpoint.
*/
static unsigned int uvc_endpoint_max_bpi(struct usb_device *dev,
struct usb_host_endpoint *ep)
{
u16 psize;
u16 mult;
switch (dev->speed) {
case USB_SPEED_SUPER:
case USB_SPEED_SUPER_PLUS:
return le16_to_cpu(ep->ss_ep_comp.wBytesPerInterval);
case USB_SPEED_HIGH:
psize = usb_endpoint_maxp(&ep->desc);
mult = usb_endpoint_maxp_mult(&ep->desc);
return (psize & 0x07ff) * mult;
case USB_SPEED_WIRELESS:
psize = usb_endpoint_maxp(&ep->desc);
return psize;
default:
psize = usb_endpoint_maxp(&ep->desc);
return psize & 0x07ff;
}
}
/*
* Initialize isochronous URBs and allocate transfer buffers. The packet size
* is given by the endpoint.
*/
static int uvc_init_video_isoc(struct uvc_streaming *stream,
struct usb_host_endpoint *ep, gfp_t gfp_flags)
{
struct urb *urb;
unsigned int npackets, i, j;
u16 psize;
u32 size;
psize = uvc_endpoint_max_bpi(stream->dev->udev, ep);
size = stream->ctrl.dwMaxVideoFrameSize;
npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
if (npackets == 0)
return -ENOMEM;
size = npackets * psize;
for (i = 0; i < UVC_URBS; ++i) {
urb = usb_alloc_urb(npackets, gfp_flags);
if (urb == NULL) {
uvc_uninit_video(stream, 1);
return -ENOMEM;
}
urb->dev = stream->dev->udev;
urb->context = stream;
urb->pipe = usb_rcvisocpipe(stream->dev->udev,
ep->desc.bEndpointAddress);
#ifndef [31mCONFIG_DMA_NONCOHERENT[0m
urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
urb->transfer_dma = stream->urb_dma[i];
#else
urb->transfer_flags = URB_ISO_ASAP;
#endif
urb->interval = ep->desc.bInterval;
urb->transfer_buffer = stream->urb_buffer[i];
urb->complete = uvc_video_complete;
urb->number_of_packets = npackets;
urb->transfer_buffer_length = size;
for (j = 0; j < npackets; ++j) {
urb->iso_frame_desc[j].offset = j * psize;
urb->iso_frame_desc[j].length = psize;
}
stream->urb[i] = urb;
}
return 0;
}
/*
* Initialize bulk URBs and allocate transfer buffers. The packet size is
* given by the endpoint.
*/
static int uvc_init_video_bulk(struct uvc_streaming *stream,
struct usb_host_endpoint *ep, gfp_t gfp_flags)
{
struct urb *urb;
unsigned int npackets, pipe, i;
u16 psize;
u32 size;
psize = usb_endpoint_maxp(&ep->desc);
size = stream->ctrl.dwMaxPayloadTransferSize;
stream->bulk.max_payload_size = size;
npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
if (npackets == 0)
return -ENOMEM;
size = npackets * psize;
if (usb_endpoint_dir_in(&ep->desc))
pipe = usb_rcvbulkpipe(stream->dev->udev,
ep->desc.bEndpointAddress);
else
pipe = usb_sndbulkpipe(stream->dev->udev,
ep->desc.bEndpointAddress);
if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
size = 0;
for (i = 0; i < UVC_URBS; ++i) {
urb = usb_alloc_urb(0, gfp_flags);
if (urb == NULL) {
uvc_uninit_video(stream, 1);
return -ENOMEM;
}
usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
stream->urb_buffer[i], size, uvc_video_complete,
stream);
#ifndef [31mCONFIG_DMA_NONCOHERENT[0m
urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
urb->transfer_dma = stream->urb_dma[i];
#endif
stream->urb[i] = urb;
}
return 0;
}
/*
* Initialize isochronous/bulk URBs and allocate transfer buffers.
*/
static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
{
struct usb_interface *intf = stream->intf;
struct usb_host_endpoint *ep;
unsigned int i;
int ret;
stream->sequence = -1;
stream->last_fid = -1;
stream->bulk.header_size = 0;
stream->bulk.skip_payload = 0;
stream->bulk.payload_size = 0;
uvc_video_stats_start(stream);
if (intf->num_altsetting > 1) {
struct usb_host_endpoint *best_ep = NULL;
unsigned int best_psize = UINT_MAX;
unsigned int bandwidth;
unsigned int uninitialized_var(altsetting);
int intfnum = stream->intfnum;
/* Isochronous endpoint, select the alternate setting. */
bandwidth = stream->ctrl.dwMaxPayloadTransferSize;
if (bandwidth == 0) {
uvc_trace(UVC_TRACE_VIDEO, "Device requested null "
"bandwidth, defaulting to lowest.\n");
bandwidth = 1;
} else {
uvc_trace(UVC_TRACE_VIDEO, "Device requested %u "
"B/frame bandwidth.\n", bandwidth);
}
for (i = 0; i < intf->num_altsetting; ++i) {
struct usb_host_interface *alts;
unsigned int psize;
alts = &intf->altsetting[i];
ep = uvc_find_endpoint(alts,
stream->header.bEndpointAddress);
if (ep == NULL)
continue;
/* Check if the bandwidth is high enough. */
psize = uvc_endpoint_max_bpi(stream->dev->udev, ep);
if (psize >= bandwidth && psize <= best_psize) {
altsetting = alts->desc.bAlternateSetting;
best_psize = psize;
best_ep = ep;
}
}
if (best_ep == NULL) {
uvc_trace(UVC_TRACE_VIDEO, "No fast enough alt setting "
"for requested bandwidth.\n");
return -EIO;
}
uvc_trace(UVC_TRACE_VIDEO, "Selecting alternate setting %u "
"(%u B/frame bandwidth).\n", altsetting, best_psize);
ret = usb_set_interface(stream->dev->udev, intfnum, altsetting);
if (ret < 0)
return ret;
ret = uvc_init_video_isoc(stream, best_ep, gfp_flags);
} else {
/* Bulk endpoint, proceed to URB initialization. */
ep = uvc_find_endpoint(&intf->altsetting[0],
stream->header.bEndpointAddress);
if (ep == NULL)
return -EIO;
ret = uvc_init_video_bulk(stream, ep, gfp_flags);
}
if (ret < 0)
return ret;
/* Submit the URBs. */
for (i = 0; i < UVC_URBS; ++i) {
ret = usb_submit_urb(stream->urb[i], gfp_flags);
if (ret < 0) {
uvc_printk(KERN_ERR, "Failed to submit URB %u "
"(%d).\n", i, ret);
uvc_uninit_video(stream, 1);
return ret;
}
}
/* The Logitech C920 temporarily forgets that it should not be adjusting
* Exposure Absolute during init so restore controls to stored values.
*/
if (stream->dev->quirks & UVC_QUIRK_RESTORE_CTRLS_ON_INIT)
uvc_ctrl_restore_values(stream->dev);
return 0;
}
/* --------------------------------------------------------------------------
* Suspend/resume
*/
/*
* Stop streaming without disabling the video queue.
*
* To let userspace applications resume without trouble, we must not touch the
* video buffers in any way. We mark the device as frozen to make sure the URB
* completion handler won't try to cancel the queue when we kill the URBs.
*/
int uvc_video_suspend(struct uvc_streaming *stream)
{
if (!uvc_queue_streaming(&stream->queue))
return 0;
stream->frozen = 1;
uvc_uninit_video(stream, 0);
usb_set_interface(stream->dev->udev, stream->intfnum, 0);
return 0;
}
/*
* Reconfigure the video interface and restart streaming if it was enabled
* before suspend.
*
* If an error occurs, disable the video queue. This will wake all pending
* buffers, making sure userspace applications are notified of the problem
* instead of waiting forever.
*/
int uvc_video_resume(struct uvc_streaming *stream, int reset)
{
int ret;
/* If the bus has been reset on resume, set the alternate setting to 0.
* This should be the default value, but some devices crash or otherwise
* misbehave if they don't receive a SET_INTERFACE request before any
* other video control request.
*/
if (reset)
usb_set_interface(stream->dev->udev, stream->intfnum, 0);
stream->frozen = 0;
uvc_video_clock_reset(stream);
if (!uvc_queue_streaming(&stream->queue))
return 0;
ret = uvc_commit_video(stream, &stream->ctrl);
if (ret < 0)
return ret;
return uvc_init_video(stream, GFP_NOIO);
}
/* ------------------------------------------------------------------------
* Video device
*/
/*
* Initialize the UVC video device by switching to alternate setting 0 and
* retrieve the default format.
*
* Some cameras (namely the Fuji Finepix) set the format and frame
* indexes to zero. The UVC standard doesn't clearly make this a spec
* violation, so try to silently fix the values if possible.
*
* This function is called before registering the device with V4L.
*/
int uvc_video_init(struct uvc_streaming *stream)
{
struct uvc_streaming_control *probe = &stream->ctrl;
struct uvc_format *format = NULL;
struct uvc_frame *frame = NULL;
unsigned int i;
int ret;
if (stream->nformats == 0) {
uvc_printk(KERN_INFO, "No supported video formats found.\n");
return -EINVAL;
}
atomic_set(&stream->active, 0);
/* Alternate setting 0 should be the default, yet the XBox Live Vision
* Cam (and possibly other devices) crash or otherwise misbehave if
* they don't receive a SET_INTERFACE request before any other video
* control request.
*/
usb_set_interface(stream->dev->udev, stream->intfnum, 0);
/* Set the streaming probe control with default streaming parameters
* retrieved from the device. Webcams that don't suport GET_DEF
* requests on the probe control will just keep their current streaming
* parameters.
*/
if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0)
uvc_set_video_ctrl(stream, probe, 1);
/* Initialize the streaming parameters with the probe control current
* value. This makes sure SET_CUR requests on the streaming commit
* control will always use values retrieved from a successful GET_CUR
* request on the probe control, as required by the UVC specification.
*/
ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
if (ret < 0)
return ret;
/* Check if the default format descriptor exists. Use the first
* available format otherwise.
*/
for (i = stream->nformats; i > 0; --i) {
format = &stream->format[i-1];
if (format->index == probe->bFormatIndex)
break;
}
if (format->nframes == 0) {
uvc_printk(KERN_INFO, "No frame descriptor found for the "
"default format.\n");
return -EINVAL;
}
/* Zero bFrameIndex might be correct. Stream-based formats (including
* MPEG-2 TS and DV) do not support frames but have a dummy frame
* descriptor with bFrameIndex set to zero. If the default frame
* descriptor is not found, use the first available frame.
*/
for (i = format->nframes; i > 0; --i) {
frame = &format->frame[i-1];
if (frame->bFrameIndex == probe->bFrameIndex)
break;
}
probe->bFormatIndex = format->index;
probe->bFrameIndex = frame->bFrameIndex;
stream->def_format = format;
stream->cur_format = format;
stream->cur_frame = frame;
/* Select the video decoding function */
if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
stream->decode = uvc_video_decode_isight;
else if (stream->intf->num_altsetting > 1)
stream->decode = uvc_video_decode_isoc;
else
stream->decode = uvc_video_decode_bulk;
} else {
if (stream->intf->num_altsetting == 1)
stream->decode = uvc_video_encode_bulk;
else {
uvc_printk(KERN_INFO, "Isochronous endpoints are not "
"supported for video output devices.\n");
return -EINVAL;
}
}
return 0;
}
/*
* Enable or disable the video stream.
*/
int uvc_video_enable(struct uvc_streaming *stream, int enable)
{
int ret;
if (!enable) {
uvc_uninit_video(stream, 1);
if (stream->intf->num_altsetting > 1) {
usb_set_interface(stream->dev->udev,
stream->intfnum, 0);
} else {
/* UVC doesn't specify how to inform a bulk-based device
* when the video stream is stopped. Windows sends a
* CLEAR_FEATURE(HALT) request to the video streaming
* bulk endpoint, mimic the same behaviour.
*/
unsigned int epnum = stream->header.bEndpointAddress
& USB_ENDPOINT_NUMBER_MASK;
unsigned int dir = stream->header.bEndpointAddress
& USB_ENDPOINT_DIR_MASK;
unsigned int pipe;
pipe = usb_sndbulkpipe(stream->dev->udev, epnum) | dir;
usb_clear_halt(stream->dev->udev, pipe);
}
uvc_video_clock_cleanup(stream);
return 0;
}
ret = uvc_video_clock_init(stream);
if (ret < 0)
return ret;
/* Commit the streaming parameters. */
ret = uvc_commit_video(stream, &stream->ctrl);
if (ret < 0)
goto error_commit;
ret = uvc_init_video(stream, GFP_KERNEL);
if (ret < 0)
goto error_video;
return 0;
error_video:
usb_set_interface(stream->dev->udev, stream->intfnum, 0);
error_commit:
uvc_video_clock_cleanup(stream);
return ret;
}